Abstract
The quantum-mechanical tunneling passing through the sub-2-nm-thick oxide in Ge/a-GeO2/Ge structures is presented, using the first-principles scattering-state method, where a stands for the amorphous phase. The suboxide interface layer (IL) between Ge and the dioxide region (DOX) does not play a critical role in blocking tunneling due to the presence of Ge - Ge bonds in it. The thickness of DOX, where all the Ge has four Ge - O bonds, is the effective tunneling-blocking thickness and the thickness for the thinnest usable a-GeO2 is approximately 0.85 nm. The width and magnitude of the band offset differently affect the tunneling in the sub-2-nm-thick oxide. The valence-band offset is larger and thicker than the conduction-band offset for all the structures, resulting in the smaller tunneling current of the holes than of the electrons. It is also found that the effect of the hydrogen passivation at the IL on tunneling is not evident in semiconductor/a-oxide. The crystallographic orientation of Ge has no distinct effect on the band-gap alignment and the tunneling current in Ge/a-GeO2/Ge structures, consistent with the experimental results about the effect of the Ge orientation on the interface properties.
| Original language | English |
|---|---|
| Article number | 034016 |
| Journal | Physical Review Applied |
| Volume | 11 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - 2019 Mar 7 |
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All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)
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Tunneling Properties of the Charge Carriers through Sub-2-nm-Thick Oxide in Ge/a - Ge O2/Ge Structures Using the First-Principles Scattering-State Method. / Ko, Eunjung; Liu, Kai; Hwang, Cheol Seong; Choi, Hyoung Joon; Choi, Jung Hae.
In: Physical Review Applied, Vol. 11, No. 3, 034016, 07.03.2019.Research output: Contribution to journal › Article
TY - JOUR
T1 - Tunneling Properties of the Charge Carriers through Sub-2-nm-Thick Oxide in Ge/a - Ge O2/Ge Structures Using the First-Principles Scattering-State Method
AU - Ko, Eunjung
AU - Liu, Kai
AU - Hwang, Cheol Seong
AU - Choi, Hyoung Joon
AU - Choi, Jung Hae
PY - 2019/3/7
Y1 - 2019/3/7
N2 - The quantum-mechanical tunneling passing through the sub-2-nm-thick oxide in Ge/a-GeO2/Ge structures is presented, using the first-principles scattering-state method, where a stands for the amorphous phase. The suboxide interface layer (IL) between Ge and the dioxide region (DOX) does not play a critical role in blocking tunneling due to the presence of Ge - Ge bonds in it. The thickness of DOX, where all the Ge has four Ge - O bonds, is the effective tunneling-blocking thickness and the thickness for the thinnest usable a-GeO2 is approximately 0.85 nm. The width and magnitude of the band offset differently affect the tunneling in the sub-2-nm-thick oxide. The valence-band offset is larger and thicker than the conduction-band offset for all the structures, resulting in the smaller tunneling current of the holes than of the electrons. It is also found that the effect of the hydrogen passivation at the IL on tunneling is not evident in semiconductor/a-oxide. The crystallographic orientation of Ge has no distinct effect on the band-gap alignment and the tunneling current in Ge/a-GeO2/Ge structures, consistent with the experimental results about the effect of the Ge orientation on the interface properties.
AB - The quantum-mechanical tunneling passing through the sub-2-nm-thick oxide in Ge/a-GeO2/Ge structures is presented, using the first-principles scattering-state method, where a stands for the amorphous phase. The suboxide interface layer (IL) between Ge and the dioxide region (DOX) does not play a critical role in blocking tunneling due to the presence of Ge - Ge bonds in it. The thickness of DOX, where all the Ge has four Ge - O bonds, is the effective tunneling-blocking thickness and the thickness for the thinnest usable a-GeO2 is approximately 0.85 nm. The width and magnitude of the band offset differently affect the tunneling in the sub-2-nm-thick oxide. The valence-band offset is larger and thicker than the conduction-band offset for all the structures, resulting in the smaller tunneling current of the holes than of the electrons. It is also found that the effect of the hydrogen passivation at the IL on tunneling is not evident in semiconductor/a-oxide. The crystallographic orientation of Ge has no distinct effect on the band-gap alignment and the tunneling current in Ge/a-GeO2/Ge structures, consistent with the experimental results about the effect of the Ge orientation on the interface properties.
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U2 - 10.1103/PhysRevApplied.11.034016
DO - 10.1103/PhysRevApplied.11.034016
M3 - Article
AN - SCOPUS:85062954928
VL - 11
JO - Physical Review Applied
JF - Physical Review Applied
SN - 2331-7019
IS - 3
M1 - 034016
ER -